*{
  margin: 0;
  padding: 0;
  font-family: '微软雅黑', sans-serif;
}
body{
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #000;
}

h2{
  color: #000;
  font-size: 6em;
  display: flex;
}

h2 span{
  animation: animate 4s linear infinite;
}

h2 span:nth-child(1){
  animation-delay: 0s;
}
h2 span:nth-child(2){
  animation-delay: 0.1s;
}
h2 span:nth-child(3){
  animation-delay: 0.2s;
}
h2 span:nth-child(4){
  animation-delay: 0.3s;
}
h2 span:nth-child(5){
  animation-delay: 0.4s;
}
h2 span:nth-child(6){
  animation-delay: 0.5s;
}
h2 span:nth-child(7){
  animation-delay: 0.6s;
}
h2 span:nth-child(8){
  animation-delay: 0.7s;
}

@keyframes animate{
  0%, 100%{
    color: #fff;
    filter: blur(2px);
    text-shadow:  0 0 10px #00b3ff,
                  0 0 20px #00b3ff,
                  0 0 40px #00b3ff,
                  0 0 80px #00b3ff,
                  0 0 120px #00b3ff,
                  0 0 200px #00b3ff,
                  0 0 300px #00b3ff,
                  0 0 300px #00b3ff;
  }
  25%, 75%{
    color: #000;
    filter: blur(0px);
    text-shadow: none;
  }
}